• Wind and Structures
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• 제16권4호
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• pp.301-322
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• 2013

Recent major post-hurricane damage assessments in the United States have reported that the most common damages result from the loss of building roof coverings and subsequent wind driven rain intrusion. In an effort to look further into this problem, this paper presents a full-scale (Wall of Wind --WoW--) investigation of external and underneath wind pressures on roof tiles installed on a low-rise building model with various gable roofs. The optimal dimensions for the low-rise building that was tested with the WOW are 2.74 m (9 ft) long, 2.13 m (7 ft) wide, and 2.13 m (7 ft) high. The building is tested with interchangeable gable roofs at three different slopes (2:12; 5:12 and 7:12). The field tiles of these gable roofs are considered with three different tile profiles namely high (HP), medium (MP), and low profiles (LP) in accordance with Florida practice. For the ridge, two different types namely rounded and three-sided tiles were considered. The effect of weather block on the "underneath" pressure that develops between the tiles and the roof deck was also examined. These tests revealed the following: high pressure coefficients for the ridge tile compared to the field tiles, including those located at the corners; considerably higher pressure on the gable end ridge tiles compared to ridge tiles at the middle of the ridge line; and marginally higher pressure on barrel type tiles compared to the three-sided ridge tiles. The weather blocking of clay tiles, while useful in preventing water intrusion, it doesn't have significant effect on the wind loads of the field tiles. The case with weather blocking produces positive mean underneath pressure on the field tiles on the windward side thus reducing the net pressures on the windward surface of the roof. On the leeward side, reductions in net pressure to a non-significant level were observed due to the opposite direction of the internal and external pressures. The effect of the weather blocking on the external pressure on the ridge tile was negligible.

• Advances in materials Research
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• 제2권1호
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• pp.65-75
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• 2013

Heterogeneous photocatalysis is a rapidly developing field in environmental engineering. It has a great potential to cope with the increasing pollution in the air. The addition of a photocatalyst to ordinary building materials such as tiles, concrete, paints, creates environmental friendly materials by which air pollution or pollution of the surface itself can be controlled and diminished. This work reports the results of the laboratory research, especially carried out towards air purifying action and self-cleaning measurements. In particular the research was focused on the study of the photocatalytic behavior of industrially prepared tiles produced starting from commercial micro-sized $TiO_2$. Air purification action has been investigated through NOx degradation tests. On the contrary, the degradation of pollution at the surface, also called as self-cleaning action, is verified by the degradation of two different organic dyes: Rhodamine B (red color) and Metanil yellow (yellow).

• 한국멀티미디어학회논문지
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• 제9권10호
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• pp.1282-1295
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• 2006

본 논문은 원 영상의 세부 묘사 유지를 위한 이미지 타일 모자이크 방법을 제안한다. 이 방법은 기존의 모자이크 방법들이 빈 공간 발생으로 인해 세부 묘사 표현의 어려움을 지니고 있는 점을 개선하였다. 이는 타일 내부의 세부 묘사를 위한 이미지 타일의 사용과 타일간의 빈 공간을 제거하기 위한 두 층의 타일 사용을 통해 구현된다. 본 논문에서 제시한 방법은 다음 세 단계로 구성된다. 첫째, 에지 회피 기법이 적용된 무게 중심 보로노이 다이어그램(CVD: Centroidal Voronoi Diagram)을 통해 위층 타일의 위치를 얻고, 딜로니 삼각형화(Delaunay Triangulation)를 이용해 아래층 타일의 위치를 계산한다. 둘째, 타일간의 관계와 에지를 고려해 타일의 크기와 방향 등의 속성을 설정한다. 셋째, 이미지 타일의 적용을 위해 포토 모자이크 기법을 사용한다. 이때, 다단계 인덱싱 기법을 통해 이미지 검객의 속도를 높인다. 위의 과정을 통해 기존의 방법들에 비해 타일 간의 빈공간이 최소화되고 타일 내부의 세부 묘사가 강화된 모자이크 영상을 얻는다.

• 대한환경공학회지
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• 제34권9호
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• pp.623-629
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• 2012

본 연구는 집수면으로 사용되는 지붕재질에 따라 집수되는 빗물의 수질을 평가하고, 지붕면에서 지의류/이끼의 존재여부에 따른 수질변화를 관찰하였다. 실험은 5가지 다른 재질의 재료[나무, 나무(이끼 서식), 콘크리트, 초벌기와, 슬레이트]로 설치된 지붕면에서 수행되었다. 각 지붕면에서의 빗물수질을 관찰한 결과, 초벌기와 지붕으로부터 집수된 빗물이 이용에 가장 적합한 재료로 나타났다. 이는 초벌기와 재질 특성에 따른 표면 온도의 상승과 자외선에 의한 살균효과 때문인 것으로 판단된다. 이끼류가 포함된 나무지붕과 일반 나무 지붕에서 집수된 빗물의 수질을 비교한 결과 이끼는 TOC, nitrate, sulfate 및 phosphate 농도에 영향을 미치는 것으로 관측되었다. 그리고 슬레이트 지붕으로부터 유출된 빗물 내 석면의 농도는 평균 0.002개/$cm^3$로 검출되었으며 이러한 결과는 환경부 다중이용시설기준 및 노동부 사무실 기준인 0.01개/$cm^3$ 규정을 만족한 것으로 나타났다.

• 한국안전학회지
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• 제6권4호
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• pp.53-57
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• 1991

Engineers of building construction have made efforts to produce more convinient building of good quality through the development of technology and raw materials nowadaye. This study is conducted to recognize problems of exterior tiles through experiments on quality of tiles according to sizes, and to find out and Iecommend most suitaff sizes of tiles. The sizes which are used widely in Construction field are selected as,45$\times$45mm, 57$\times$87mm, 60$\times$108mm, 60$\times$187mm, 96$\times$200mm. Ready mixed compound are used as mortar and Compressed attachment method are used.

• Advances in environmental research
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• 제9권4호
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• pp.285-294
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• 2020

Growth of any country rest in the consumption of industrial wastes for its infrastructure amenities. Countries like India positively desires a vital utilization of industrial waste resembling paper sludge in the construction industry to make various building materials. Also, it is the duty of all civil engineers or researchers to attach them in mounting new materials from the waste dumped as land fillings. In every construction project, about 70% of cost accounts for the procurement of materials. If this, can be minimized consequently the cost of construction will certainly be condensed. Research has established that the waste paper sludge can be reused in the construction field for a probable scope. The construction diligences munch through a massive quantity of non-renewable resources. On the additional dispense, more waste paper board sludge ends up in landfills or dumpsites than those recycled. Consequently, waste paper sludge for use as a construction material composes a step towards sustainable development. Keeping this in mind an endeavor has been made to utilize paper board sludge acquired from the paper board industry and used with several pozzolanic and cementitious materials for a specific purpose. The addition of paper sludge has been varied from 0% to 20% by weight of cement. The tests done with the samples expose that four samples showed significant outcomes with remarkable strength and durability properties which guide to move for the next phase of research for producing lightweight tiles.

• Journal of applied mathematics & informatics
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• 제17권1_2_3호
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• pp.343-350
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• 2005

In this paper we prove two results about tilings of orthogonal polygons. (1) P be an orthogonal polygon with rational vertex coordinates and let R(u) be a rectangle with side lengths u and 1. An orthogonal polygon P can be tiled with similar copies of R(u) if and only if u i algebraic and the real part of each of its conjugates is positive; (2) Laczkovich proved that if a triangle $\Delta$ tiles a rectangle then either $\Delta$ is a right triangle or the angles of $\Delta$ are rational multiples of $\pi$. We generalize the result of Laczkovich to orthogonal polygons.

• Wind and Structures
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• 제17권2호
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• pp.185-202
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• 2013

The goal of this study was to investigate the vulnerability of roof tile systems and metal shutters to roof tile debris. Three phases addressed the performance of tile roof systems and metal shutters impacted by roof tile debris. The first phase experimentally evaluated the tile fragment size and quantity generated by a tile striking a tile roof system. The second phase experimentally quantified the puncture vulnerability of common metal panel shutter systems as a function of tile fragment impact speed. The third phase provided context for interpretation of the experimental results through the use of a tile trajectory model. The results provide supporting evidence that while metal panel window shutters provide significant protection against a prevalent form of windborne debris, these systems are vulnerable to tile fragment puncture in design level tropical cyclones. These findings correlate with field observations made after Hurricane Charley (2004).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.692-697
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• 2000

Recently, Flat flame burners are hilighted in high-load burners. Our study contains flow field analysis of a flat flame burner. In this paper, We analyzed the direction and magnitude of the velocity in a round tile type burner with swirl angles, $10^{\circ},\;30^{\circ},\;50^{\circ}$. In the case of swirl angle $10^{\circ}$, because axial momentum is larger than radial momentum, Recirculation region was weakly developed. In the case of swirl angle $50^{\circ}$, Flow in front of the tile is distributed for radial direction. And Recirculation region is large. So, We expect that the radiation can be transmitted from tiles and the recirculation region may cause $NO_x$ reduction.

• 수산해양기술연구
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• 제48권2호
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• pp.174-179
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• 2012

A new absorption material, cellulose sponge soaked in cement, was made for anechoic water tank and its acoustical properties were investigated by pulse methods. The sound absorption coefficient a (dB/cm) of the material was obtained in the frequency range of 40~120kHz from the echo reduction ER (dB) and insertion loss IL (dB) data. The result was averagely 1.8dB/cm higher than the sound absorption coefficient a (dB/cm) of cork-filled rubber which is one of the most effective absorption materials. The wedge (1.2~5.0cm long) type absorption tiles were made with this new material. The echo reduction ER (dB) of the absorption tile with 5.0cm wedge measured in water tank was higher than 20dB in the experimental frequency range.